[PATCH 1/2] drm/panfrost: Make sure MMU context lifetime is not bound to panfrost_priv
Boris Brezillon
boris.brezillon at collabora.com
Tue Feb 4 14:47:39 UTC 2020
On Tue, 4 Feb 2020 15:35:03 +0100
Boris Brezillon <boris.brezillon at collabora.com> wrote:
> Jobs can be in-flight when the file descriptor is closed (either because
> the process did not terminate properly, or because it didn't wait for
> all GPU jobs to be finished), and apparently panfrost_job_close() does
> not cancel already running jobs. Let's refcount the MMU context object
> so it's lifetime is no longer bound to the FD lifetime and running jobs
^its
> can finish properly without generating spurious page faults.
>
> Reported-by: Icecream95 <ixn at keemail.me>
> Fixes: 7282f7645d06 ("drm/panfrost: Implement per FD address spaces")
> Cc: <stable at vger.kernel.org>
> Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
> ---
> drivers/gpu/drm/panfrost/panfrost_device.h | 8 +-
> drivers/gpu/drm/panfrost/panfrost_drv.c | 50 ++-----
> drivers/gpu/drm/panfrost/panfrost_gem.c | 20 ++-
> drivers/gpu/drm/panfrost/panfrost_job.c | 4 +-
> drivers/gpu/drm/panfrost/panfrost_mmu.c | 158 ++++++++++++++-------
> drivers/gpu/drm/panfrost/panfrost_mmu.h | 5 +-
> 6 files changed, 135 insertions(+), 110 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
> index 06713811b92c..3f19288e8375 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> @@ -94,8 +94,12 @@ struct panfrost_device {
> };
>
> struct panfrost_mmu {
> + struct panfrost_device *pfdev;
> + struct kref refcount;
> struct io_pgtable_cfg pgtbl_cfg;
> struct io_pgtable_ops *pgtbl_ops;
> + struct drm_mm mm;
> + spinlock_t mm_lock;
> int as;
> atomic_t as_count;
> struct list_head list;
> @@ -106,9 +110,7 @@ struct panfrost_file_priv {
>
> struct drm_sched_entity sched_entity[NUM_JOB_SLOTS];
>
> - struct panfrost_mmu mmu;
> - struct drm_mm mm;
> - spinlock_t mm_lock;
> + struct panfrost_mmu *mmu;
> };
>
> static inline struct panfrost_device *to_panfrost_device(struct drm_device *ddev)
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index 273d67e251c2..41e574742a3c 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -418,7 +418,7 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
> * anyway, so let's not bother.
> */
> if (!list_is_singular(&bo->mappings.list) ||
> - WARN_ON_ONCE(first->mmu != &priv->mmu)) {
> + WARN_ON_ONCE(first->mmu != priv->mmu)) {
> ret = -EINVAL;
> goto out_unlock_mappings;
> }
> @@ -450,32 +450,6 @@ int panfrost_unstable_ioctl_check(void)
> return 0;
> }
>
> -#define PFN_4G (SZ_4G >> PAGE_SHIFT)
> -#define PFN_4G_MASK (PFN_4G - 1)
> -#define PFN_16M (SZ_16M >> PAGE_SHIFT)
> -
> -static void panfrost_drm_mm_color_adjust(const struct drm_mm_node *node,
> - unsigned long color,
> - u64 *start, u64 *end)
> -{
> - /* Executable buffers can't start or end on a 4GB boundary */
> - if (!(color & PANFROST_BO_NOEXEC)) {
> - u64 next_seg;
> -
> - if ((*start & PFN_4G_MASK) == 0)
> - (*start)++;
> -
> - if ((*end & PFN_4G_MASK) == 0)
> - (*end)--;
> -
> - next_seg = ALIGN(*start, PFN_4G);
> - if (next_seg - *start <= PFN_16M)
> - *start = next_seg + 1;
> -
> - *end = min(*end, ALIGN(*start, PFN_4G) - 1);
> - }
> -}
> -
> static int
> panfrost_open(struct drm_device *dev, struct drm_file *file)
> {
> @@ -490,15 +464,11 @@ panfrost_open(struct drm_device *dev, struct drm_file *file)
> panfrost_priv->pfdev = pfdev;
> file->driver_priv = panfrost_priv;
>
> - spin_lock_init(&panfrost_priv->mm_lock);
> -
> - /* 4G enough for now. can be 48-bit */
> - drm_mm_init(&panfrost_priv->mm, SZ_32M >> PAGE_SHIFT, (SZ_4G - SZ_32M) >> PAGE_SHIFT);
> - panfrost_priv->mm.color_adjust = panfrost_drm_mm_color_adjust;
> -
> - ret = panfrost_mmu_pgtable_alloc(panfrost_priv);
> - if (ret)
> - goto err_pgtable;
> + panfrost_priv->mmu = panfrost_mmu_ctx_create(pfdev);
> + if (IS_ERR(panfrost_priv->mmu)) {
> + ret = PTR_ERR(panfrost_priv->mmu);
> + goto err_free;
> + }
>
> ret = panfrost_job_open(panfrost_priv);
> if (ret)
> @@ -507,9 +477,8 @@ panfrost_open(struct drm_device *dev, struct drm_file *file)
> return 0;
>
> err_job:
> - panfrost_mmu_pgtable_free(panfrost_priv);
> -err_pgtable:
> - drm_mm_takedown(&panfrost_priv->mm);
> + panfrost_mmu_ctx_put(panfrost_priv->mmu);
> +err_free:
> kfree(panfrost_priv);
> return ret;
> }
> @@ -522,8 +491,7 @@ panfrost_postclose(struct drm_device *dev, struct drm_file *file)
> panfrost_perfcnt_close(file);
> panfrost_job_close(panfrost_priv);
>
> - panfrost_mmu_pgtable_free(panfrost_priv);
> - drm_mm_takedown(&panfrost_priv->mm);
> + panfrost_mmu_ctx_put(panfrost_priv->mmu);
> kfree(panfrost_priv);
> }
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> index 17b654e1eb94..406e595f99e4 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> @@ -60,7 +60,7 @@ panfrost_gem_mapping_get(struct panfrost_gem_object *bo,
>
> mutex_lock(&bo->mappings.lock);
> list_for_each_entry(iter, &bo->mappings.list, node) {
> - if (iter->mmu == &priv->mmu) {
> + if (iter->mmu == priv->mmu) {
> kref_get(&iter->refcount);
> mapping = iter;
> break;
> @@ -74,16 +74,13 @@ panfrost_gem_mapping_get(struct panfrost_gem_object *bo,
> static void
> panfrost_gem_teardown_mapping(struct panfrost_gem_mapping *mapping)
> {
> - struct panfrost_file_priv *priv;
> -
> if (mapping->active)
> panfrost_mmu_unmap(mapping);
>
> - priv = container_of(mapping->mmu, struct panfrost_file_priv, mmu);
> - spin_lock(&priv->mm_lock);
> + spin_lock(&mapping->mmu->mm_lock);
> if (drm_mm_node_allocated(&mapping->mmnode))
> drm_mm_remove_node(&mapping->mmnode);
> - spin_unlock(&priv->mm_lock);
> + spin_unlock(&mapping->mmu->mm_lock);
> }
>
> static void panfrost_gem_mapping_release(struct kref *kref)
> @@ -94,6 +91,7 @@ static void panfrost_gem_mapping_release(struct kref *kref)
>
> panfrost_gem_teardown_mapping(mapping);
> drm_gem_object_put_unlocked(&mapping->obj->base.base);
> + panfrost_mmu_ctx_put(mapping->mmu);
> kfree(mapping);
> }
>
> @@ -145,11 +143,11 @@ int panfrost_gem_open(struct drm_gem_object *obj, struct drm_file *file_priv)
> else
> align = size >= SZ_2M ? SZ_2M >> PAGE_SHIFT : 0;
>
> - mapping->mmu = &priv->mmu;
> - spin_lock(&priv->mm_lock);
> - ret = drm_mm_insert_node_generic(&priv->mm, &mapping->mmnode,
> + mapping->mmu = panfrost_mmu_ctx_get(priv->mmu);
> + spin_lock(&mapping->mmu->mm_lock);
> + ret = drm_mm_insert_node_generic(&mapping->mmu->mm, &mapping->mmnode,
> size >> PAGE_SHIFT, align, color, 0);
> - spin_unlock(&priv->mm_lock);
> + spin_unlock(&mapping->mmu->mm_lock);
> if (ret)
> goto err;
>
> @@ -178,7 +176,7 @@ void panfrost_gem_close(struct drm_gem_object *obj, struct drm_file *file_priv)
>
> mutex_lock(&bo->mappings.lock);
> list_for_each_entry(iter, &bo->mappings.list, node) {
> - if (iter->mmu == &priv->mmu) {
> + if (iter->mmu == priv->mmu) {
> mapping = iter;
> list_del(&iter->node);
> break;
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index 4d383831c1fc..b0716e49eeca 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -154,7 +154,7 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
> return;
> }
>
> - cfg = panfrost_mmu_as_get(pfdev, &job->file_priv->mmu);
> + cfg = panfrost_mmu_as_get(pfdev, job->file_priv->mmu);
> panfrost_devfreq_record_busy(pfdev);
>
> job_write(pfdev, JS_HEAD_NEXT_LO(js), jc_head & 0xFFFFFFFF);
> @@ -481,7 +481,7 @@ static irqreturn_t panfrost_job_irq_handler(int irq, void *data)
> if (job) {
> pfdev->jobs[j] = NULL;
>
> - panfrost_mmu_as_put(pfdev, &job->file_priv->mmu);
> + panfrost_mmu_as_put(pfdev, job->file_priv->mmu);
> panfrost_devfreq_record_idle(pfdev);
>
> dma_fence_signal_locked(job->done_fence);
> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> index 763cfca886a7..f70d5a75cbd5 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> @@ -1,5 +1,8 @@
> // SPDX-License-Identifier: GPL-2.0
> /* Copyright 2019 Linaro, Ltd, Rob Herring <robh at kernel.org> */
> +
> +#include <drm/panfrost_drm.h>
> +
> #include <linux/atomic.h>
> #include <linux/bitfield.h>
> #include <linux/delay.h>
> @@ -332,7 +335,7 @@ static void mmu_tlb_inv_context_s1(void *cookie)
>
> static void mmu_tlb_sync_context(void *cookie)
> {
> - //struct panfrost_device *pfdev = cookie;
> + //struct panfrost_mmu *mmu = cookie;
> // TODO: Wait 1000 GPU cycles for HW_ISSUE_6367/T60X
> }
>
> @@ -354,56 +357,10 @@ static const struct iommu_flush_ops mmu_tlb_ops = {
> .tlb_flush_leaf = mmu_tlb_flush_leaf,
> };
>
> -int panfrost_mmu_pgtable_alloc(struct panfrost_file_priv *priv)
> -{
> - struct panfrost_mmu *mmu = &priv->mmu;
> - struct panfrost_device *pfdev = priv->pfdev;
> -
> - INIT_LIST_HEAD(&mmu->list);
> - mmu->as = -1;
> -
> - mmu->pgtbl_cfg = (struct io_pgtable_cfg) {
> - .pgsize_bitmap = SZ_4K | SZ_2M,
> - .ias = FIELD_GET(0xff, pfdev->features.mmu_features),
> - .oas = FIELD_GET(0xff00, pfdev->features.mmu_features),
> - .tlb = &mmu_tlb_ops,
> - .iommu_dev = pfdev->dev,
> - };
> -
> - mmu->pgtbl_ops = alloc_io_pgtable_ops(ARM_MALI_LPAE, &mmu->pgtbl_cfg,
> - priv);
> - if (!mmu->pgtbl_ops)
> - return -EINVAL;
> -
> - return 0;
> -}
> -
> -void panfrost_mmu_pgtable_free(struct panfrost_file_priv *priv)
> -{
> - struct panfrost_device *pfdev = priv->pfdev;
> - struct panfrost_mmu *mmu = &priv->mmu;
> -
> - spin_lock(&pfdev->as_lock);
> - if (mmu->as >= 0) {
> - pm_runtime_get_noresume(pfdev->dev);
> - if (pm_runtime_active(pfdev->dev))
> - panfrost_mmu_disable(pfdev, mmu->as);
> - pm_runtime_put_autosuspend(pfdev->dev);
> -
> - clear_bit(mmu->as, &pfdev->as_alloc_mask);
> - clear_bit(mmu->as, &pfdev->as_in_use_mask);
> - list_del(&mmu->list);
> - }
> - spin_unlock(&pfdev->as_lock);
> -
> - free_io_pgtable_ops(mmu->pgtbl_ops);
> -}
> -
> static struct panfrost_gem_mapping *
> addr_to_mapping(struct panfrost_device *pfdev, int as, u64 addr)
> {
> struct panfrost_gem_mapping *mapping = NULL;
> - struct panfrost_file_priv *priv;
> struct drm_mm_node *node;
> u64 offset = addr >> PAGE_SHIFT;
> struct panfrost_mmu *mmu;
> @@ -416,11 +373,10 @@ addr_to_mapping(struct panfrost_device *pfdev, int as, u64 addr)
> goto out;
>
> found_mmu:
> - priv = container_of(mmu, struct panfrost_file_priv, mmu);
>
> - spin_lock(&priv->mm_lock);
> + spin_lock(&mmu->mm_lock);
>
> - drm_mm_for_each_node(node, &priv->mm) {
> + drm_mm_for_each_node(node, &mmu->mm) {
> if (offset >= node->start &&
> offset < (node->start + node->size)) {
> mapping = drm_mm_node_to_panfrost_mapping(node);
> @@ -430,7 +386,7 @@ addr_to_mapping(struct panfrost_device *pfdev, int as, u64 addr)
> }
> }
>
> - spin_unlock(&priv->mm_lock);
> + spin_unlock(&mmu->mm_lock);
> out:
> spin_unlock(&pfdev->as_lock);
> return mapping;
> @@ -537,6 +493,106 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
> return ret;
> }
>
> +static void panfrost_mmu_release_ctx(struct kref *kref)
> +{
> + struct panfrost_mmu *mmu = container_of(kref, struct panfrost_mmu,
> + refcount);
> + struct panfrost_device *pfdev = mmu->pfdev;
> +
> + spin_lock(&pfdev->as_lock);
> + if (mmu->as >= 0) {
> + pm_runtime_get_noresume(pfdev->dev);
> + if (pm_runtime_active(pfdev->dev))
> + panfrost_mmu_disable(pfdev, mmu->as);
> + pm_runtime_put_autosuspend(pfdev->dev);
> +
> + clear_bit(mmu->as, &pfdev->as_alloc_mask);
> + clear_bit(mmu->as, &pfdev->as_in_use_mask);
> + list_del(&mmu->list);
> + }
> + spin_unlock(&pfdev->as_lock);
> +
> + free_io_pgtable_ops(mmu->pgtbl_ops);
> + drm_mm_takedown(&mmu->mm);
> + kfree(mmu);
> +}
> +
> +void panfrost_mmu_ctx_put(struct panfrost_mmu *mmu)
> +{
> + kref_put(&mmu->refcount, panfrost_mmu_release_ctx);
> +}
> +
> +struct panfrost_mmu *panfrost_mmu_ctx_get(struct panfrost_mmu *mmu)
> +{
> + kref_get(&mmu->refcount);
> +
> + return mmu;
> +}
> +
> +#define PFN_4G (SZ_4G >> PAGE_SHIFT)
> +#define PFN_4G_MASK (PFN_4G - 1)
> +#define PFN_16M (SZ_16M >> PAGE_SHIFT)
> +
> +static void panfrost_drm_mm_color_adjust(const struct drm_mm_node *node,
> + unsigned long color,
> + u64 *start, u64 *end)
> +{
> + /* Executable buffers can't start or end on a 4GB boundary */
> + if (!(color & PANFROST_BO_NOEXEC)) {
> + u64 next_seg;
> +
> + if ((*start & PFN_4G_MASK) == 0)
> + (*start)++;
> +
> + if ((*end & PFN_4G_MASK) == 0)
> + (*end)--;
> +
> + next_seg = ALIGN(*start, PFN_4G);
> + if (next_seg - *start <= PFN_16M)
> + *start = next_seg + 1;
> +
> + *end = min(*end, ALIGN(*start, PFN_4G) - 1);
> + }
> +}
> +
> +struct panfrost_mmu *panfrost_mmu_ctx_create(struct panfrost_device *pfdev)
> +{
> + struct panfrost_mmu *mmu;
> +
> + mmu = kzalloc(sizeof(*mmu), GFP_KERNEL);
> + if (!mmu)
> + return ERR_PTR(-ENOMEM);
> +
> + mmu->pfdev = pfdev;
> + spin_lock_init(&mmu->mm_lock);
> +
> + /* 4G enough for now. can be 48-bit */
> + drm_mm_init(&mmu->mm, SZ_32M >> PAGE_SHIFT, (SZ_4G - SZ_32M) >> PAGE_SHIFT);
> + mmu->mm.color_adjust = panfrost_drm_mm_color_adjust;
> +
> + INIT_LIST_HEAD(&mmu->list);
> + mmu->as = -1;
> +
> + mmu->pgtbl_cfg = (struct io_pgtable_cfg) {
> + .pgsize_bitmap = SZ_4K | SZ_2M,
> + .ias = FIELD_GET(0xff, pfdev->features.mmu_features),
> + .oas = FIELD_GET(0xff00, pfdev->features.mmu_features),
> + .tlb = &mmu_tlb_ops,
> + .iommu_dev = pfdev->dev,
> + };
> +
> + mmu->pgtbl_ops = alloc_io_pgtable_ops(ARM_MALI_LPAE, &mmu->pgtbl_cfg,
> + mmu);
> + if (!mmu->pgtbl_ops) {
> + kfree(mmu);
> + return ERR_PTR(-EINVAL);
> + }
> +
> + kref_init(&mmu->refcount);
> +
> + return mmu;
> +}
> +
> static const char *access_type_name(struct panfrost_device *pfdev,
> u32 fault_status)
> {
> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.h b/drivers/gpu/drm/panfrost/panfrost_mmu.h
> index 44fc2edf63ce..cc2a0d307feb 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.h
> @@ -18,7 +18,8 @@ void panfrost_mmu_reset(struct panfrost_device *pfdev);
> u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu);
> void panfrost_mmu_as_put(struct panfrost_device *pfdev, struct panfrost_mmu *mmu);
>
> -int panfrost_mmu_pgtable_alloc(struct panfrost_file_priv *priv);
> -void panfrost_mmu_pgtable_free(struct panfrost_file_priv *priv);
> +struct panfrost_mmu *panfrost_mmu_ctx_get(struct panfrost_mmu *mmu);
> +void panfrost_mmu_ctx_put(struct panfrost_mmu *mmu);
> +struct panfrost_mmu *panfrost_mmu_ctx_create(struct panfrost_device *pfdev);
>
> #endif
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